The present invention relates to an apparatus for the disposal of hazardous wastes, by decomposition of the materials using an extremely high temperature plasma arc furnace, and subsequent treatment of the decomposed residue to control the carbon byproducts.
A prior art patent which describes one form of an apparatus and process for disposing of waste material in this manner is U.S. Pat. No. 4,644,877, issued Feb. 24, 1987, which describes a system for feeding waste materials into a plasma arc burner furnace where the materials are atomized and ionized, and then discharging the residue into a reaction chamber to be cooled and recombined into a product gas and particulate matter which is non-toxic. The recombined products are quenched with an alkaline atomized spray to neutralize the products and to wet the particulate matter. The product gas is extracted from the recombined products, and the extracted product gas is burned. The patent describes a form of construction of the apparatus which is xe2x80x9ccompactxe2x80x9d in size, permitting the device to made sufficiently small so as to be mobile and transportable to a hazardous waste site in a 45-foot truck or trailer. The patent does not describe an apparatus or process for addressing the problem of carbon formation during the process, nor does it disclose any method or apparatus for sensing or controlling carbon formation.
Another form of hazardous waste processing system is described in U.S. Pat. No. 5,319,176, issued Jun. 7, 1994. In this patent, a product of the process is carbon black, which is created and controlled by steam injection into the waste material stream during the burning process. The patent describes a dual plasma arc system, wherein one furnace is used for pyrolysis and a second chamber is used for secondary off-gas processing which produces a carbon black byproduct.
Another prior art patent which discloses a typical construction for a plasma arc furnace of the type of interest herein is U.S. Pat. No. 5,534,659, issued Jul. 9, 1996, to Springer et al.
In view of the foregoing patents, and other prior art in the field, it would provide a distinct advantage to have a hazardous material plasma arc furnace with as small a physical form as possible, and to provide such a processing system with sensors and control mechanisms for controlling the amount of carbon byproduct created by the processing system.
An apparatus and method for destroying hazardous waste products in a plasma electric arc furnace of small physical size, using water quenching to cool the process gases and a carbon sensor in the process flow path to monitor carbon buildup, and a control mechanism to control carbon loading of the process materials. The furnace has a discharge and quench assembly which directs the furnace exhaust in a wrap-around path, and utilizes three water injection sprayers at various positions along the path for cooling, and utilizes a carbon sensor in the flow path which monitors flow path pressure to detect carbon buildup, and controls materials in the flow path as needed to maintain a low amount of carbon buildup.
It is a principal object of the invention to provide a compact hazardous material disposal system which does not release hazardous materials into the atmosphere.
It is a further object of the invention to provide a waste disposal system wherein the amount of carbon buildup can be controlled.
It is another object of the invention to provide a plasma arc furnace for destroying hazardous materials where the destruction residue can be quickly and efficiently cooled after thermal processing.